<?php  
//即static::静态方法名();如果子类有该方法,那么调用子类的静态方法,否则如果父类有就调用父类,子类和父类都没有就报错
 
class TopPerson{
    public $id;
    public $name;
    public $email;
    // public $phone;
    // public $address;
    // public $address2;
    // public $city;
    // public $state;
    // public $zip;
    // public $country;
    public static function test(){
        echo self::who();
    }
    public static function test1(){
         static::who();
    }
    public static function who(){
        echo __CLASS__ .PHP_EOL;
    }
    public static function o(){
        echo __CLASS__ .PHP_EOL;
    }

}
class Person extends TopPerson{
    public static function who(){
        echo __CLASS__ .PHP_EOL;
    }

    
    public static function test3(){
        static::who();
   }
    public static function test4(){
        static::o();
   }
}

Person::test();
Person::test1();
Person::test3();
Person::test4();

